You need one of those cockrings with two rings-a small one for your dick, linked to a larger one for your balls.

Put the cockring around your dick and then put your just balls through the larger ring (i.e. don't put the large ring around your dick and balls).

Pull your scrotum through the larger ring at the bottom. This way you end up with your balls nice and tight between the two rings, and it will also pull the skin on your dick's right back, exposing that sensitive skin normally inside the foreskin. You'll look as if you've got a high and tight cut with the inner skin and frenlum intact.